1. Field of the Invention
This invention relates generally to a treatment for patella subluxation and/or tilt, and more particularly, to a method for treating this patella displacement through the introduction of a neurotoxin into the fibrous tissue of a knee joint, with an optional additional step of manual manipulation of the patella, and subsequent realignment of the patella for rapid knee pain relief without surgery.
2. Description of the Related Art
Patella instability, namely subluxation or tilting of the patella relative to the femur, is a common progressive displacement condition of the patella, occurring in all age groups. It is at times referred to as “anterior knee pain” of unknown origin, and at times as “lateral tracking syndrome”. Normal alignment of the patella 2 relative to the femur 1 and tibia 3 is shown in FIGS. 1-3. With reference to FIG. 4, patella tilt is a progressive condition where the patella 2 gradually becomes laterally displaced and/or tilted relative to and against the femur 1, placing abnormal pressure on the ridge of the lateral femoral condyle 5. There are varying degrees of lateral patella tilting or subluxation. Regardless of severity, abnormal patella positioning and tilting produces an abnormal lateral and, or tilted tracking of the patella 2 against the femur 1 wherein the patella 2 glides over the lateral femoral condyle 5 rather than down in the patellofemoral groove 4. When the patella 2 becomes displaced over the lateral femoral condyle 5, at times called by the name “lateral patella tracking syndrome” or “patella compression syndrome”, this causes the patella 2 to exert a progressively compressive force on the lateral femoral condyle or sulcus 5. This patella condition causes a characteristic breakdown of the articular cartilage of the patella 2 resulting in aching, grinding or pain that is typically vague in location and can extend proximally into the thigh muscles and distally into the calf muscles.
With reference to FIGS. 2-4, the knee has four muscles, the rectus femoris (not shown), the vastus lateralis 6, vastus intermedius 7 and vastus medialis 8. When walking, running or climbing, the vastus lateralis 6 pulls the patella 2 laterally, resulting in chronic thickening and contracture of the vastus lateral retinaculum 9, which is the fibrous tissue that extends from the vastus lateralis 6 into the knee joint area. Fibrous tissue in general is a connective tissue, and may comprise ligaments or tendons. In the knee joint, fibrous tissue plays a role in maintaining the patella 2 in proper alignment. Abnormalities in the fibrous tissue of the knee, such as the lateral retinaculum 9, may cause or aggravate patellar subluxation. For example, the lateral pulling of the patella 2 caused by thickening or contracture of the lateral retinaculum 9 prevents the patella 2 from properly gliding in the patellofemoral groove 4 and displaces the patella 2 over the lateral femoral condyle or sulcus 5, producing compressive forces that start the process of breaking down the articular cartilage.
Patella lateral positioning, or subluxation, may also occur as a result of damage to fibrous tissue of the knee, such as when the medial retinaculum snaps or is torn. In this situation, the corresponding lateral retinaculum 9 may overcompensate and exert a force on the patella 2 which is stronger than normal, effectively pulling the patella 2 laterally out of natural alignment and thereby producing subluxation. In another example, the fibrous tissue on the lateral side of the knee may spasm uncontrollably, or contract and be unable to relax for a period of time. This spasming or prolonged contraction may effectively pull the patella 2 from the patellofemoral groove 4, thus inducing subluxation. Moreover, the misalignment of the patella 2 cannot abate until the affected fibrous tissue, such as the lateral retinaculum 9, has been restored to its natural relaxed state.
Patellar subluxation has been traditionally treated with orally administered medication, surgery and, or knee braces. Initially, activity is limited while having the patient take medication, such as aspirin or other anti-inflammatory medicine. This approach rarely works. If the patient does not improve with these conservative measures, then surgery is typically required. The most common surgical technique is a lateral retinacular release, whereby the lateral retinaculum 9 is divided surgically by making an incision along the dotted line shown in FIG. 2.
Surgery is not always successful. It is expensive and requires a long recovery time. Knee braces are also undesirable, as they are uncomfortable and typically fail to resolve the problem. If a nonsurgical solution existed for treating a patella positioning abnormality to provide rapid knee pain relief through patellar realignment, it would avoid these shortcomings and be well received.
Unfortunately, there are no previously known practical non-surgical options for treating patella subluxation or providing rapid relief. For instance, U.S. Pat. No. 4,423,720, issued to Meier et al, discloses a patellar stabilizing orthosis brace used in conjunction with rehabilitation programs involving all nonsurgical patella dislocations or mal-alignments including chondromalacia patellae, dislocation of the patella or subluxation of the patella. U.S. Pat. No. 4,607,628, issued to Dashefsky, discloses a knee brace and includes a patella support pad positioned to engage a lateral edge of the patella. U.S. Pat. No. 5,554,105, issued to Taylor, discloses a patella stabilizer having a sleeve worn around the knee. U.S. Pat. No. 4,777,946, issued to Watanabe et al., discloses a gadget for the remedy and prevention of knee joint trouble accompanied by the movement of the patella, comprising a patella fixing member and a connecting belt wound round the knee to fix the patella fixing member thereon. U.S. Pat. No. 6,287,269, issued to Osti et al., discloses an orthesis device for the conservative treatment of patellofemoral instability of the knee. U.S. Pat. No. 6,589,248, issued to Hughes, discloses a patellar alignment device for determining the position of a patella prosthesis comprising a baseplate and a mobile component which is magnetically attached to the baseplate. U.S. Pat. No. 7,004,741, issued to Gaylord et al., discloses an apparatus for stabilizing movement of the patella in the patellofemoral joint comprising a base having an opening, a buttress secured to the base sheet member, a tensioning member secured to the base sheet member, a pair of tensioning arms secured to the buttress, a pair of tensioning arms secured to the tensioning member, a pair of compression members formed from the base, and a stabilizing member secured to an edge of the base. U.S. Pat. No. 7,048,741, issued to Swanson, discloses a method for performing an operative, minimally invasive knee arthroplasty comprising the steps of creating an incision along the medial or lateral aspect of a patient's knee, exposing the knee joint, resecting the distal end of the femur, the proximal end of the tibia and the posterior patella through the medial or lateral incision, and connecting a femoral, tibial and patellar knee replacement component through the incision.
Pursuant to the foregoing, a practical non-surgical or braceless method for reliably and effectively treating patella subluxation does not exist. Accordingly, there exists a need for such a procedure. The instant invention addresses this unfulfilled need in the prior art by providing a nonsurgical procedure for treating and alleviating patella subluxation and, or tilt as contemplated by the instant invention disclosed herein.